Carter Carburetor Adjustments

Q: Carter Carburetor Adjustments

The carter carb is very similiar if not almost identical to an edelbrock 600 cfm carb. I really need assistance and desperately. One of the questions is about the two screws on the front of the carb at the base. What should these screws be turned to? The carb has an electric choke and how should this be set? And would there be any other adjustments that I could do to it? I seem to be getting much poorer fuel mileage that the stock carter carb that was on the 326. I bought this new carb thinking I would increase mileage but has turned just the opposite!! This could be because I do not have it adjusted right. I really would appreciate any help that someone can give. Thanks.

A: The two screws on the front are the idle mixture screws turning them out (counter-clockwise) will richen the mixture & vice versa.They have no effect on the mixture at cruise(in otherwards if its too rich at driving speeds adjusting these will not help) as for setting them,the only real “correct way” is with an exhaust gas analyzer.Setting with a vacuum guage may work but likely the smoothest idle will be too rich if your state does emission testing.Having said that try turning the screws in one at a time (with the engine off) & counting the number of turns on each(In a perfect world they should be the same) then back them both out to the smaller number of turns.Now restart the car (which should have been already warmed up).Now try turning both of the screws 1/2 a turn in,if the car starts running rougher you are too lean (& you should back the screws out again & try going out in 1/2 turn increments until you find it makes no further improvement then go back in 1/2 a turn or so),if the idle improves try another 1/2 turn until you find where it starts to run rough then back the screws out 1/2 turn or so.Basically you are trying for the smoothest idle & then (slightly) leaning the mixture.

As for the choke setting,basically you want the choke valve to just close on a long cool off (sitting overnight or a number of hours) this is assuming that the weather is mild (so when it is really cold it will be closed with more tension).The plate should be open completely after approx 5 minutes running time no more than 10 anyhow. I hope this helps..

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